WASHINGTON - The top House Republican made a modest but important break with President Bush yesterday over the budget, endorsing billions of dollars in added spending.

The surprise development removed one hurdle from among the many standing in the way of Congress completing its budget work.

House Minority Leader John A. Boehner (R., Ohio) has been perhaps Bush's most loyal ally in his months-long battle with congressional Democrats on the budget. His remarks came as a surprise to the White House but reflected a realistic assessment of the budget battlefield on Capitol Hill.

Boehner endorsed adding funding above Bush's budget for border security, foreign aid, and State Department operations in Iraq and Afghanistan, and for other purposes. These "emergency" funds are supposed to reflect one-time needs and not be permanent fixtures in the budget.

Boehner says he remains committed to supporting Bush vetoes of any catchall spending bill that tops his budget request.

"It all passes the straight-face test," Boehner said in supporting the emergency items. Later, a spokesman said Boehner did not necessarily support the entire bundle of emergency spending.

The emergency funding drew a protest Saturday from White House budget director Jim Nussle as he issued a veto threat on a $522 billion catchall spending bill.

That measure, under negotiation for weeks, would have halved, to $11 billion, the spending increases sought by Democrats above Bush's request for the agency budgets that Congress passes each year. The proposed $7.4 billion in emergency money - most of which has its strongest support from Republicans - would have brought the total above Bush's budget to $18 billion.

A White House budget office spokesman, Sean Kevelighan, said, "Our position has not changed - hold government spending to the president's reasonable and responsible levels and fund our troops in the field."

After the veto threat, House Appropriations Committee Chairman David R. Obey (D., Wis.) threatened to tear up the omnibus bill to fit Bush's budget numbers, but by cutting GOP priorities and killing billions of dollars in lawmakers' hometown projects.

Obey's idea seemed to be losing momentum yesterday, receiving a cool reception in the earmark-craving Senate.

Under budget rules, emergency spending comes atop budget limits set by Congress to deal with unanticipated events such as natural disasters or unexpected shortfalls in federal programs. In practice, it has often been used to skirt budget limits.